Lubricant



Patented Dec. 21, 1943 LUBRICANT Bert H. Lincoln, Ponca City, Okla., and Gordon D.- Byrkit, Niagara Falls, N. Y., assignors, by mesne assignments. to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Original application March 14, 1940,

Serial No. 323,960. Divided and this application April 15, 1942, Serial No. 439,094

1 Claim.

This invention has to do with the improvement of lubricants and is more particularly concerned with lubricant compositions which have been improved in various characteristics, such as resistance to oxidation and to the formation of cor rosive products during use, by the incorporation therein of a minor proportion of a characterizing ingredient. This application is a division of our copending application Serial No. 323,960, filed March 14, 1940, now Patent Number 2,297,658, issued September 29, 1942, which in turn was a continuation-in-part of our application Serial No. 231,362, filed September 23, 1938.

Present-day mechanical devices require lubricating oils of high film strength, of high oiliness characteristics, and of low tendency to oxidize during use. It has been found that the presentday hydrocarbon lubricants .of the very highest quality are deficient in these very important characteristics. These three properties are of vital importance under conditions of thin film lubrication where the lubricant has been squeezed from between the friction surfaces because of high pressure, slow speeds, and other causes. It is readily seen that the viscosity or the body of the lubricant plays no part in this type of lubrication and that the remaining film of oil must have a .very high film strength and be of high oiliness value to prevent rupture of the film of the lubricant, which would cause seizure. The oil film must tend to keep the coefficient of friction as low' as possible. The oil must resist oxidation when these thin films are heated in th presence V that an invention which provides a means of 11m proving the film strength of these lubricants is of great importance to the art of lubricant manufacture and to the designer and fabricator of mechanical devices.

Substantially all machines operate in part or at times totally under conditions of boundary or thin film lubrication, under which conditions the oiliness or unctuosity of the lubricant is the first and primary requisite of efficient operation. Those skilled in the art of lubricant manufacture or machine manufacture will readily appreciate the value of an invention that will improve the oiliness of these otherwise high-quality lubricants. cially deleterious under conditions of thin film lubrication. The sludge is not a lubricant in any senseof the word, and the soluble acid is particularly corrosive to hearing metals such as cad-- mium-silver, copper-lead, and the like.

Furthermore, sludge and acid are espe- In starting idle mechanical equipment which is lubricated from a sump by pumping or circulating the lubricant, there is always a short period of time in which the rubbing surfaces must operate under conditions of dry friction if ordi-- nary hydrocarbon lubricants are used. With drt friction, the wear on friction surface is extreme; and during cold weather when the lubricant issluggish or during periods when the lubricating system is not functioning properly for one reason or another, rubbing surfaces may not only suffer considerable wear but may be damaged to the point where they .must be replaced. The.

product of our invention has a very important property of reacting with the metal surfaces,

penetrating or adsorbing on the metal surfaces,

with unburned fuel or with other light hydrocarbons, the small degree of oiliness of the original hydrocarbon lubricant is greatly decreased. We have found that the addition of the products of our invention tohydrocarbon lubricants more than compensates for the loss in oiliness and load-- carrying ability from dilution.

. It' is well known that, in order to obtain lubricants which are preeminently satisfactory from the standpoint of oxidation in use, it is necessary to refine the oil thoroughly and then to add an inhibitor of oxidation. The thorough refining may consist of more and heavier acid treatments i or solvent treating so as to remove a considerable part of the oil and leave only the most stable portion. Such drastic refining is necessary in order to obtain stability with respect to sludge formation, but the oil is then subject to easy oxidation to form soluble acids and other corrosive I materials. This can be prevented by the addi-'- tion to the refined oil of small amounts of materials which either prevent the formation of these corrosive products or by the same action render them inert. Furthermore, such wellrefined oils are susceptible to the formation during use of lacquerlike materials which tend to stick rings. 'This results in a blow-by and hence loss of power, failure of lubrication, scratching;

scoring, overheating, and eventually replacement of these difl'lculties, namely, sludge, soluble corro sive products, and lacquer. It is considerably addition to lubricants.

analogues.

more advantageous to add-the materials of our invention and avoid these difliculties by this method. 1

in the limitations set forth above may be used within the scope of our invention.

Many of these additive materials are effective I when added to poorly refined or even'wholly unrefined lubricants. substituted in whole or in part of the usual refining'processes.

In the prior are of applying these principles to the manufacture of lubricants, many diverse Theaddends may thus be It is, to be understood that in practicing our invention, oil-soluble 'organo-arsenic-nitrogen -ether compounds .of the type described are to be selected. Some of the examples described have only limited solubility in hydrocarbon oils. It is to be remembered, however, that, because of their types of materials have been suggested to be added to obtain improvement in various char.- acteristics. It has been found that the addition of various organic esters of the oxygen and sulfur acids of phosphorus frequently improves fllm strength, oxidation, resistance, no'n cor-. rosiveness, and other, characteristics. Nitrogen compounds have been found toinhibit oxidation of oils. Our materials combine both of these properties.

One object of our invention is to provide improved inhibitors of oxidation and corrosion for Another object of our invention is to provide fllm strength improving addition agents suitable for use in lubricants and especially in,crankcase lubricants. j Y

Other and further objects of our invention will appear in the course of the following descrip tion. In general, our invention involves the use of certain'organic arsenic compounds containing at least one arsenic-nitrogen bond to hydrocarbon 'fuels and lubricants. We have discovered that these materials which may be broadly charsented by the general formula? (RNH) nAs(O R ')a-n in whichR represents an aromatic or an alkylsubstituted aromatic radical; n is the integer one or two and R represents an organic radical." or

the general class of ethers represented by the foregoing formula, preference is given to the diethers corresponding to the general formula RNH.As(OR')2 in which R and R have the same significance defined above. Listed below are sev.-

eral representative examples of compounds of the type contemplated herein. *All and each of-these are to be considered as examples of our invention when blended in-an oil of lubricating viscosity.

Examples Arsen-anilino dimethyl ether C6H5NH-AS(OCH3) z Arsen-toluidino dicresyl ether CHaCsH4NH.AS(OCsH4CHa) i (3) Arsen-p-tert.-butyl anilino dilauryl ether C4 Ho.CsH4NH.As(OC12H35)2 Arsen-anilino dibenzyl -;e't her Any of these compounds or other members of the classesnepresented or derivatives with-" great efiiciency, extremely small amounts are often effective. Thus, we may use as little as 0.001 per cent of some of these compounds, and

it will be seen that a fairly insoluble material may dissolve to a sufllcient extent to be satisfac- .tory for our purpose. I

0.001 percent of our \addition agentsv are used,

In general, more than and we may add one, two or even five per cent or more.

Furthermore, it is well known that different types of oils have different capabilities of dis- For some purposes,-

solving a given material. therefore, we prefer paraflinic lubricants, while for other purposes we prefer naphthenic or mixed base lubricants. Another method ofobtaining a satisfactory mixture of addition agent with the hydrocarbon'oil is the use of a mutualsolvent to bring the addend into solution. Alternatively, peptizing agents may be added to maintain the organo-arsenic compound in permanent suspension.

Many of the more diflicultlysoluble materials are rendered more soluble by the introduction of alkyl groups, particularly those containing four or more carbon atoms. The iso-amyl, octyl,

' lauryl, and octadecyl radicals and radicals from ether is much more soluble.

paraflin "wax greatly increase the solubility of organic compounds in oil. One or more of such groups may be introduced as required into the previously described compounds or" their de- For example, arsen-anilino dimethyl rivatives. ether is not very soluble in hydrocarbon lubricating oils but arsen-p-tert.-butylanilino dilauryl The selection of a particular compound or compounds to be used as an addition agent to the hydrocarbon oil ismore or less dependent upon the use to which the blend is to be put.

Thus, if water is likely to be present during use, an arsen-aryl amino ether compound or combination of compounds is selected which is not afl'ected by water. In general, we prefer to use 7 compounds having boiling points over 250 F. It is sometimes advantageous to combine more than one of these compounds in a blend to obtain particular' properties. We accomplish this by mixing two or more of these compounds together K and blending the mixture with the hydrocarbon voil or by blending one in the hydrocarbon oil,

blending the second into this mixture, and so on until the composition is complete.

The various arsen-aryl. amino ether compounds contemplated herein usually improve both the film strength and oxidation characteristics of the hydrocarbon 011. For example, the sludging tendencies may be decreased by as little I as 0.001 per cent of the arsen-aryl amino ether compounds. The oxidation characteristics of lubricants are very important, and these are .markedly improved by minor proportions of our small amounts compounds- The ability to reduce friction is another feature contributed to lubricants by of our arsenic-nitrogen com- It may be desirable to include in one and the same blend based on a hydrocarbon oil, in addition totheaddends here described, other addends glycerol, water, lamp black, mica, zinc dust,

for specific purposes. Thus, we may add a pour point depressor such as a naphthalene-chlorwax condensation product and a viscosity index improver such as certain resins or polymerized hydrocarbons addition to our prgano-arsenic compounds. Furthm'more, various other metallic compounds may be added to the blend without interfering with the action of our ingredients. Indeed,- in some cases, it is advantageous to combine with our organic arsenic-nitrogen compounds in a hydrocarbon oil blend such materials as calcium dichloro-stearate, chromium oleate, tin octadecyl phthalate, aluminum stearate, and other metallic soaps.

Our addends are admirably adapted for use in lubricating oils 'of all types including those designed for use in automotive crankcases,

Diesel oils, and any other oils of lubricating viscosity such as castor oil, cotton seed oil, lard oil, sperm oil, shale oil. Furthermore, our addends are advantageously blended in gasoline and other petroleum fuels, either directly or after being blended first'in a lubricating oil and then added to the fuel.. Soap-thickened mineral oils of all types ranging from those showing only a slight increase in viscosity over that of themineral oil alone to the semi-solid and solid greases containing fifty per cent or more of soap are amenable to treatment according to our invention.- In making these greases,-

. may be added. These include yarn, hair graphite,

litharge, and the like.

The following example illustrates one type of lubricant composition in which improving agents .of the type contemplated herein may be used.

It is to be understood, of course, that this example is merely illustrative and in no way limits the scope of the invention because, as aforesaid, the arsen-aryl amino ethers may be used with or without other addends in the oil composition.

Ezample Per cent Paraflln base bright stock 57.0 Paramn base neutral stock 40.0 Sulfurized methyl esters of corn oil esters 1.1

Arsen-anilino dimethyl ether 0.2 Calcium. dichloro-stearate 1 3 Diphenyl-chlorwax condensation product-.. 0.4

vention is not limited to the'examples given but includes within its scopewhatever changes fairly come within the spirit of the appended claim.

We claim:

A lubricant comprising in combination a major I proportion of oil of lubricatingviscosity and a minor proportion of arsen-anilino dibenzyl ether.

BERT H.1INCOI1N. GORDON n. BYRKIT. 

